DETERMINATION OF DYNAMIC STRAIN HARDENING PARAMETERS USING THE VIRTUAL FIELDS METHOD

Abstract

The aim of the present study is to propose a procedure for identifying dynamic strain hardening parameters using the virtual fields method (VFM) so as to provide more accurate hardening properties at high strain rates for automotive crash analysis simulations. In order to validate the procedure, a proper elasto-plastic constitutive model was adopted and simulated measurements were obtained using a finite element (FE) analysis program. The same identification procedure as that which will be implemented in the experiments was applied. The VFM was used as an inverse analytical tool to retrieve the constitutive parameters. Since precise measurement of the applied load is not an easy task at high strain rates due to the inertial effect, the identification was carried out using the acceleration fields without utilizing load information. A sensitivity study was conducted to assess the effect of several experimental conditions on the identification. Then, the identified parameters using the VFM were compared with the target ones, which were fed into the FE simulations. Very promising results were obtained using the VFM.